Device for operating a combustion device, such as a space heater

ABSTRACT

An apparatus for operating a combustion device, such as a space heater, comprises an electric motor operated blower for the combustion air as well as for the space heating air, and which has a rotatable blower shaft with electric impulse generator means associated therewith. The impulse generator may comprise, for example, an electrical coil which is located alongside the blower which is operated by the rotation of a magnet or magnets carried on the blower periphery. The impulse generator is connected via an amplifier to an igniter and also to an electromagnetically operated fuel pump. The pulses which are generated are used to actuate the igniter and to operate the fuel pump in the necessary time sequence.

United States Patent Siegfried 1 Feb. 19, 1974 [75] Inventor: Kofink Siegfried, Zell/Neckar,

Germany [73] Assignee: J. Eberspacher, Esslingen, Neckar Germany [22] Filed: Oct. 16, 1972 [21] Appl. No.: 298,007

[30] Foreign Application Priority Data Aug. 6, 1971 Germany P 21 39 513.1

[52] US. Cl. 431/1, 431/255 [51] Int. Cl. F23c 3/02 [58] Field of Search 431/254, 255, 1, 28

[56] References Cited UNITED STATES PATENTS 3,024,835 3/1962 Ryder 431/1 1,137,328 4/1915 Jennings 3,255,804 6/1966 Lang 431/1 3,169,570 2/1965 Haag et al 431]] Primary ExaminerEdward G. Favors Attorney, Agent, or FirmMcGlew and Tuttle [5 7 ABSTRACT An apparatus for operating a combustion device, such as a space heater, comprises an electric motor operatedblower for the combustion air as well as for the space heating air, and which has a rotatable blower shaft with electric impulse generator means associated therewith. The impulse generator may comprise, for example, an electrical coil which is located alongside the blower which is operated by the rotation of a magnet or magnets carried on the blower periphery. The impulse generator is connected via an amplifier to an igniter and also to an electromagnetically operated fuel pump. The pulses which are generated are used to actuate the igniter and to operate the fuel pump in the necessary time sequence.

5 Claims, 1 Drawing Figure [([CT/Q/C IMPULSE TRANS/MINER IGNI TEE PULSE DIV/DER -14 DEVICE FOR OPERATING A COMBUSTION DEVICE, SUCH AS A SPACE HEATER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to the construction of combustion devices and, in particular, to a new and useful apparatus for controlling the combustion in a device, such as a space heater.

2. Description of the Prior Art At the present time, motor drive combustion space heaters are known which include interrupters for generating the electrical pulses for the spark plug ignition and which operate off the drive shaft of the blower motor. In such instances, the pulses of lower frequency for the electromagnetic metering pump for the fuel are generated by a second interrupter contact actuated indirectly through a reduction gear by the drive shaft of the blower motor. Such a known device for generating the speed proportional electrical pulses through mechanically actuated interrupter contacts is relatively complicated and expensive and the necessity for a reduction gear requires a relatively greater additional expense and the maintenance costs for its operation are high.

SUMMARY OF THE INVENTION The invention provides a heater, particularly a space heater, of atype used in a motor vehicle, which is of simple construction and which is composed predominately of electronic components for the simultaneous generation of electrical pulses both for the ignition and for the operation of the fuel pumps. With the inventive arrangement, only a single pulse transmitter is necessary for operating both the igniter and the metering pump for the fuel. The pulse transmitter is actuated to generate electrical impulses as a function of the speed of the blower motor and thus is proportional to the combustion air supply. The lower pulse frequency, which is necessary for driving the fuel pump, in view of the relatively low fuel supply per unit of time which must be delivered, is generated by a pulse divider. Except for the actual transmitter part of the pulse transmitter which is associated with the blower shaft, the entire control device can be composed of purely electronic components and thus it can be realized very simply and inexpensively and made so that it operates with very little maintenance and is wear-free. The control apparatus of the invention can be installed very easily as a unit in existing heaters of this kind.

Accordingly, it is an object of the invention to provide an apparatus for operating a combustion device, such as a space heater, which comprises an electric motor operated blower for the combustion air with an electric impulse generator associated with the blower so that it generates electrical impulses in timed relation to the speed thereof for operating both an igniter for igniting the fuel which is delivered to the combustion device and an electric pulse operated fuel pump for delivering the fuel.

A further object of the invention is to provide an electronic pulse generating device for use in a combustion device, such as a space heater, which is simple in design, rugged in construction and economical to manufacture.

For an understanding of the principles of the invention, reference is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The only FIGURE of the drawing is the schematic view indicating the apparatus for generating driving pulses for the igniter and fuel pump of a combustion device, such as a space heater, constructed in accordance with the invention.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing in particular, the invention embodied therein, comprises an apparatus for operating a combustion device, such as a space heater, which for example, may comprise an additional heater in a motor vehicle or similar construction. The heater includes an igniter or ignition device, generally designated 1, which generally comprises an ignition coil, which is connected to a spark plug arranged in the combustion chamber of the heater (not shown). The combustion device is supplied with fuelin metered quantities by an electric impulse operated .pump 2, which is operated electromagnetically by current pulses so that it delivers a regular pulse quantity of fuel to the combustion device.

In accordance with the invention, the combustion device includes a blower motor 3, having a drive shaft 6, which drives a fresh air blower wheel 4 at one end, and a combustion air blower wheel or fan 5 at the opposite end. Electric pulse generating means are associated with the drive shaft 6 and, in the embodiment shown, it comprises an electric pulse transmitter 7, which generates pulses which are delivered through an output line 10 in proportion to the frequency of the speed of rotation of the shaft 6 and hence of the combustion air blower delivery speed. In the embodiment shown, the pulse transmitter 7 comprises a permanent magnet 8 which is disposed on the blower wheel 5 and cooperates with the stationary induction coil 9-connected to the output line 10, so that an electric pulse is generated for each revolution of the shaft.lnstead of an induction coil 9, a magnetically controllable resistance or similar electric element may be employed. In the simplest form, the pulse transmitter 7 may comprise an interrupter contact which lies in the suitable control circuit and is actuated directly by the shaft 6. Such a purely mechanical design of the pulse transmitter 7 is not as advantageous as the indirectly actuated pulse transmitter of the invention wherein the pulses are generated by the magnet 8 as it moves past the coil 9 during the rota tion of the combustion fan 5.

In the usual heater construction, the blower motor 3 generally runs at a speed of about 5000 and 6000 rpm. When using a single permanent magnet 8, this corresponds to a pulse frequency of about Hz. Several magnets may be distributed around the blower wheel 5 in a circumferential direction or several induction coils, or magnetic resistances, may be distributed at circumferentially spaced locations around the fan in order to obtain variations of the pulse frequency, if desired.

The output electrical pulses which are delivered to the line 10 are amplified in a pulse amplifier 1 1 and fed through a line 12 directly to the igniter 1. Additional pulse forming is not necessary in this case as the pulses for the igniter 1 should generally be relatively narrow and only of high amplitude. For the metering pump 2, on the other hand, rectangular pulses of a certain duration and a low sequential frequency are necessary. usually in the order of magnitude of from between 3 and Hz. This is so that the fuel supply to the combustion chamber can be uniformly delivered in small quantities, for example, from 0.3 to 1.5 liters per hour. The output pulses of the pulse amplifier 11 are therefore fed through the line 13 to a pulse divider 14 which transforms input pulses into rectangular pulses. In the example shown, the pulse divider has, for example, a dividing ratio of 1:20. With an input frequency of 100 Hz. This corresponds to an output frequency proportional to the speed of rotation of the shaft 6 of about 5 Hz on the output line 15, which leads directly to the metering pump 2.

in some heaters, the igniter 1 can be disconnected after starting and, for this purpose, a switch 16 in the line 12, which can be actuated by a thermostat, for example, is provided. When the switch 16 is opened, due to the formation of a flame of a particular characteristic in the combustion device, only the metering pump 2 is driven by the output pulses of the pulse transmitter 7.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A device for operating a combustion device, such as a space heater, comprising an electric motor operated blower for combustion air having a rotatable blower shaft, electrical impulse generator means associated with said blower shaft and operable in timed relation to the speed of rotation of said shaft to generate timed electrical impulses, an electric pulse operated fuel pump connected to said generator for operation thereby in timed sequence to deliver metered quantities of fuel to the combustion device, and an igniter for igniting the fuel which is delivered to the combustion device connected to said impulse generator for igniting the fuel in definite timed relation to the speed of rotation of said blower shaft.

2. A device for operating a combustion device, according to claim 1, including a pulse divider connected between said impulse generator and said fuel pump.

3. A device for operating a combustion device, such as a space heater, comprising an electric motor operated blower for combustion air having a rotatable blower shaft, electrical impulse generator means associated with said blower shaft and operable in timed relation to the speed of rotation of said shaft to generate timed electrical impulses, an electric pulse operated fuel pump connected to said generator for operation thereby in timed sequence to deliver metered quantities of fuel to the combustion device, and an igniter for igniting the fuel which is delivered to the combustion device connected to said impulse generator for igniting the fuel in definite timed relation to the speed of rotation of said blower shaft, said pulse transmitter including a magnet carried on said blower, and a stationary induction coil arranged to be influenced by the field of the magnet as it rotates with said blower to generate an electric pulse when it is subjected to the field of the magnet.

4. A device for operating a combustion device, according to claim 3, wherein said induction coil comprises a magnetically controllable resistance.

5. A device for operating a combustion device, such as a space heater, comprising an electric motor operated blower for combustion air having a rotatable blower shaft, electrical impulse generator means associated with said blower shaft and operable in timed relation to the speed of rotation of said shaft to generate timed electrical impulses, an electric pulse operated fuel pump connected to said generator for operation thereby in timed sequence to deliver metered quantities of fuel to the combustion device, and an igniter for igniting the fuel which is delivered to the combustion device connected to said impulse generator for igniting the fuel in definite timed relation to the speed of rotation of said blower shaft, and a pulse amplifier connected between said impulse generator and said igniter and said fuel pump. 

1. A device for operating a combustion device, such as a space heater, comprising an electric motor operated blower for combustion air having a rotatable blower shaft, electrical impulse generator means associated with said blower shaft and operable in timed relation to the speed of rotation of said shaft to generate timed electrical impulses, an electric pulse operated fuel pump connected to said generator for operation thereby in timed sequence to deliver metered quantities of fuel to the combustion device, and an igniter for igniting the fuel which is delivered to the combustion device connected to said impulse generator for igniting the fuel in definite timed relation to the speed of rotation of said blower shaft.
 2. A device for operating a combustion device, according to claim 1, including a pulse divider connected between said impulse generator and said fuel pump.
 3. A device for operating a combustion device, such as a space heater, comprising an electric motor operated blower for combustion air having a rotatable blower shaft, electrical impulse generator means associated with said blower shaft and operable in timed relation to the speed of rotation of said shaft to generate timed electrical impulses, an electric pulse operated fuel pump connected to said generator for operation thereby in timed sequence to deliver metered quantities of fuel to the combustion device, and an igniter for igniting the fuel which is delivered to the combustion device connected to said impulse generator for igniting the fuel in definite timed relation to the speed of rotation of said blower shaft, said pulse transmitter including a magnet carried on said blower, and a stationary induction coil arranged to be influenced by the field of the magnet as it rotates with said blower to generate an electric pulse when it is subjected to the field of the magnet.
 4. A device for operating a combustion device, according to claim 3, wherein said induction coil comprises a magnetically controllable resistance.
 5. A device for operating a combustion device, such as a space heater, comprising an electric motor operated blower for combustion air having a rotatable blower shaft, electrical impulse generator means associated with said blower shaft and operable in timed relation to the speed of rotation of said shaft to generate timed electrical impulses, an electric pulse operated fuel pump connected to said generator for operation thereby in timed sequence to deliver metered quantities of fuel to the combustion device, and an igniter for igniting the fuel which is delivered to the combustion device connected to said impulse generator for igniting the fuel in definite timed relation to the speed of rotatioN of said blower shaft, and a pulse amplifier connected between said impulse generator and said igniter and said fuel pump. 